As electronic and computer technology continues to evolve, communication of information to a user at all times becomes increasingly important. For example, now more than ever users of personal digital assistants (PDAs) are continuously checking email, looking-up contacts, drafting documents on-the-go, and scheduling. Other users are utilizing mobile phones with built-in PDAs. In addition to these new devices, more and more users are using tablet PCs and notebook computers. The mobility of the powerful computing devices makes them ideal for the business traveler. A general computing system for a mobile device will now be described.
A. Computing System
FIG. 1A shows an embodiment of a mobile computing system 100. The computing system includes a Central Processing Unit (CPU) 101, a cache 102, a memory controller and bridge 103 and a system memory 104. Software instructions performed by the computing system (and its corresponding data) are stored in the system memory 104 and cache 102 (where frequently used instructions and data are stored in cache 102). The software instructions (together with corresponding data) are executed by the CPU 101. The memory controller portion of the memory controller and bridge function 103 is responsible for managing access to the system memory 104 (which may be used by functional elements other than the CPU 101 such as the graphics controller 105 and various I/O units).
The graphics controller 105 and display 106 provide the computer generated images observed by the user of the computing system 100. The bridge portion of the memory controller and bridge function 103 provides a system bus 107 that multiple Input/Output (I/O) units 1081 through 108N may use to communicate with one another, the CPU 101, the system memory 104, etc. I/O buses 1091 through 109N also interconnects I/O units 108, through 108N to the system bus 107. Here, I/O units are typically viewed as functional units that send/receive information to/from the computing system (e.g., a networking adapter, a MODEM, a wireless interface, a keyboard, a mouse, etc.) and/or function units used for storing information within the computing system 100 (e.g., a hard disk drive unit). Note that the depiction of FIG. 1A is exemplary and other computing system architectures are possible (e.g., multiprocessor computing systems, for example).
Buses 107 and 1091, through 109N may be bus structures, such as a Universal Serial Bus (USB) bus, in order to couple a keyboard, mouse and other lower performance peripherals. Also, “parallel” and/or “serial” ports (not shown in FIG. 1A for simplicity) may also be viewed as additional I/O units.
B. Bluetooth Wireless Network
FIG. 1B illustrates a prior art wireless network 1000. Network 1000 includes a mobile computing system 1100, such as described illustrated in FIG. 1A. Computing system 1100 communicates with multiple Bluetooth enabled devices, such as mobile phone 1300, personal digital assistant (PDA) 1200, or similar multifunction Bluetooth enabled device.
Mobile computing system 1100 communicates with Bluetooth devices 1200 and 1300 using Universal Serial Bus (USB) Bluetooth Adapter 1140, Personal Computer Memory Card International Association (PCMCIA) Bluetooth card 1120, or an internal Bluetooth adapter.
Bluetooth is a computing and telecommunications industry specification that describes how mobile phones, computers, and PDAs can easily interconnect with each other and with home and business phones and computers using a short-range wireless connection. Using this technology, users of cellular phones, pagers, and personal digital assistants such as the PalmPilot will be able to buy a three-in-one phone that can double as a portable phone at home or in the office, get quickly synchronized with information in a desktop or notebook computer, initiate the sending or receiving of a fax, initiate a print-out, and, in general, have all mobile and fixed computer devices be totally coordinated.
Bluetooth requires that a low-cost transceiver chip be included in each device. The transceiver transmits and receives in a previously unused frequency band of 2.45 GHz that is available globally (with some variation of bandwidth in different countries). In addition to data, up to three voice channels are available. Each device has a unique 48-bit address from the IEEE 802 standard. Connections can be point-to-point or multipoint. The maximum range is 10 meters. Data can be exchanged at a rate of 1 megabit per second (up to 2 Mbps in the second generation of the technology). A frequency hop scheme allows devices to communicate even in areas with a great deal of electromagnetic interference. Built-in encryption and verification is provided.